Previous experiments in our laboratories have indicated that quantitative and video analysis of surface fluorescence from atherosclerotic necropsy specimens provides a means for sensitive differentiation of normal and atherosclerotic segments. These data indicate that surface fluorescence emissions are reduced from atherosclerotic zones and this changes can be displayed quantitatively as well as visually utilizing video enhanced images employing a custom design microscope spectrofluorimeter. The present investigation was designed to analyze surface fluorescence changes associated with laser-induced atheroma ablation. Both argon and excimer lasers were employed and plaque was removed form necropsy human specimens of aorta containing varying degrees of surface atheroma. We found that plaque removal was associated with increased fluorescence intensity and that residual intima thickness after laser ablation was strongly associated with fluorescence intensity. Moreover, transmural analysis of plaque failed to identify important plaque-related fluorochromes which might be responsible for the observed fluorescence emissions. We concluded that laser atheroma ablation returns surface fluorescence to normal and that plaque appears to behave as an absorbing internal filter decreasing autofluorescence from elastic fibers in the underlying media. Thus, surface fluorescence intensity may be a useful technique to monitor plaque removal during laser angioplasty.